1. Field of the Invention
The present invention relates to an interrupter circuit arrangement for high-frequency signals, the arrangement comprising a switching circuit having a high-frequency signal path which includes at least one attenuation diode (more specifically PIN diodes), and a control terminal at which is received control signals from a control circuit for adjusting switching circuit to the conductive or the nonconductive state. A biasing circuit ensures that the high-frequency signals and the control signals are decoupled. The control circuit supplies the control signals in response to a command voltage applied thereto. Such signals are derived from either a first voltage source to render the signal path conductive or from a second voltage source to render it nonconductive.
Such an interrupter circuit arrangement can be used to great advantage. For example, several such arrangements can be combined to switch a high-frequency signal transmitter to various different load circuits.
2. Description of the Related Art
An arrangement of this type is described in U.S. Pat. No. 3,912,949. In said Patent it is recommended, in order to accelerate the change-of-state (conductive, non-conductive and nonconductive, conductive) to produce current peaks to retrieve the charge stored in the PIN diodes. Although this is very efficient for high-frequency signals of a low power, it is not applicable to signals of a high power (of the order of 100 Watts). Actually, at such a power, to ensure that the PIN diodes do not become conductive again in response to high frequency voltage peaks, whereas they should be non-conductive, it is necessary to provide a second blocking voltage source of a high value, exceeding the peak value of the high-frequency voltages. It is then possible to create, unless precautions are taken, current peaks which generate overvoltages which, when added to the high value of the second voltage source, may produce a considerable risk of causing breakdown of the PIN diodes.
In addition, it is important to provide an appropriate decoupling between the high-frequency signals, and the control signals, which in practice means that a bypass capacitance is necessary at the control terminal so as to shunt the high-frequency signals. Applicants have found that this capacitance is responsible for slowing down the supply of the control signals to the electrodes of the PIN diode(s).